CARDIOVASCULAR PATHOLOGY 3 Flashcards
What is hypertension ?
High blood pressure
What is blood pressure determined by ?
The cardiac output and the vascular resistance
What is the aim of hypertensive medication ?
To control cardiac output and vascular resistance
Name three vascular changes which can increase vascular resistance ?
Atheroma
Hypertrophy
Increased reactivity in resistance vessels
What is primary hypertension ?
Where the cause it not known
What is secondary hypertension ?
When the cause is known
What % of hypertension cases are secondary ?
10-20%
Can hypertension be cured?
Only secondary if the cause is removed
What conditions can cause secondary hypertension ?
Renal disease Kidney disease Cortication of the aorta Pheochromocytoma Cushing syndrome Hyperthyroidism Recreational drugs Oral contraception's Corticosteroids
What is Pheochromocytoma ?
a small vascular tumour of the adrenal medulla, causing irregular secretion of adrenalin and noradrenaline
What is Cushing syndrome ?
Too much cortisol in the body
What features of hypertension suggest that it might be secondary ?
- Severe
- Resistant
- Decaling
- Malignant hypertension
- Young people
- No risk factors
Can hypertension be acute as well as chronic ?
Yes it can be a medical emergency
What is an example of a hypertensive medical emergency ?
Malignant hypertension
Describe Malignant hypertension
BP of 180/120 and evidence of acute organ damage
How is malignant hypertension treated ?
Lower BP by 10-20% in first hour
Lower to 160/100 in the next six hours.
This is done suing IV antihypertensives until target is met and then the patient is switched over to a oral medication
What can happen if you decrease BP too quickly ?
Increased chance of morbidity and mortality
When might a rapid reduction in BP be required ?
In ischemic stroke or aortic dissection
What is high BP which arises in pregnancy called?
gestational hypertension
What is high BP which was present before pregnancy called?
Chronic Hypertension
What is the second most common cause of maternal and foetal death ?
Gestational hypertension
What condition can result from high blood pressure in pregnancy ?
Pre-eclampsia.
Describe pre-eclampsia
A rapid rise in BP after 20 weeks gestation
BP > 140/90
Proteinuria > 300mg/24hrs
How is pre-eclampsia treated?
Antihypertensives
How is gestational hypertension and pre-eclampsia treated?
Antihypertensives and close monitoring
What are some risk factors for hypertension ?
Hypercholesteremia
Older age
Obesity
What are the signs and symptoms of hypertension ?
High BP Headaches SOB retinopathy or visual changes chest pain
What investigations are carried out to diagnose hypertension ?
20-30 BP readings using a ABPM or a HBPM
Assign risk calculator
Urinalysis to check for renal function
Serology to check for renin
What is a nocturnal dip?
When there is a reduction in blood pressure overnight.
What does a loss of nocturnal dip suggest ?
Organ damage i.e. Kidneys and heart
What is white coat hypertension ?
when a patient has a high BP at the doctors because of stress but a normal BP the rest of the time
What is masked hypertension ?
when a patient has a normal BP at the doctors but a high BP the rest of the time
What does the assign risk calculator do ?
used to work out the risk of a patient suffering a major cardiac event in the next 10 years.
What is stage 1 hypertension ?
ABPM daytime average Stage 1 hypertension = BP ≥ 135/85
What is stage 2 hypertension ?
Stage 2 hypertension = BP ≥ 140/90
What is stage 3 hypertension ?
Stage 3 hypertension = BP ≥ 180/120
What are some non-pharmacological treatments for hypertension ?
exercise, reduced salt intake, good diet, limited alcohol, smoking cessation
When should phrenological treatments be started ?
CVD risk is ≥10% over the next 10 years
What is the aim of treatment ?
get BP <135/85 or <145/85 in > 80 year olds
What is the antihypertensive of choice for a person of African/Carrabin family origin ?
Thiazide a diuretic
What is the antihypertensive of choice for a person over 55 yo or of child bearing capacity ?
A CCB
What is the antihypertensive of choice for a person under 55 yo ?
ACEI
How is stage 1 hypertension treated ?
antihypertensive of choice in those over 80 or those with target organ damage, establish CVS disease, renal disease or a 10% risk of a major CVS event in the next 10 years
How is stage 2 hypertension treated ?
Stage 2 hypertension is treated with an antihypertensive for all.
Describe how hypertensive treatment can be escalated ?
If treatment doesn’t work then thiazide can be added to a CCB or ACEI/ARB. If that still doesn’t work then you can consider using CCB, ACEI and a diuretic which is a very powerful combination.
Name two common ACEIs
Ramipril and perindopril
How doe ACEIs work ?
They Inhibit the actions of ACE (lowering BP). ACEIs can have ADRs with NSAIDs causing acute renal failure.
What are some contraindications of ACEIS?
Renal impairment,
Fertile females,
What is the made side effect of an ACEI?
Main side effect is a dry cough
What are ARBs?
They can be used instead of an ACEI where a patient cant have an ACEI
Name a few ARBs
losartan, valsartan and candesartan
Describe ARBs
competitively block angiotensin II at the angiotensin AT1 receptors. ARBs are similar to ACEIs but don’t produce a cough
Names some common CCBs
amlodipine or felodipine
How do CCBs work ?
Calcium allows myocyte contraction in blood vessels and heart. CCBs bind to L type channels in the myocytes preventing calcium from acting of the myocytes and therefore reducing contraction, decreasing HR and causing vasodilation
Common side effects of CCBs
cause flushing, headaches, ankle oedema, indigestion etc especially in women
Contraindications of CCBs
MI, heart failure, bradycardia
Name 1 example of a thiazide
indapamide
How does thiazide work ?
They enhance urinary excretion of sodium but they may take a number of week before the full effects are felt.
Complications of a thiazide
Gout and ED
What is Atheroma/Atherosclerosis ?
an elevated lesion or plaque on the intima or a large or medium sized artery
Where do Atheroma/Atherosclerosis usually form ?
at the branching or bifurcation points where there is turbulent flow
What does atheroma do to the vessel diameter ?
Reduces it
Describe the process by which an atheroma forms
In arteries endothelial cells become injured or dysfunction. This allow LDL from the plasma to move into the tunica intima of the blood vessels. The presence of LDL in the intima causes endothelial cells to release molecules which oxidise the LDL. Oxidised LDL causes the endothelial cells express leukocytes adhesion molecules on there surface. Monocytes and T-helper cells bind to the endothelial receptors and move into the intima. Monocytes become macrophages and engulf the oxidised LDL and become ‘foam cells’. Foam cells have a number of roles including stimulating the migration and proliferation of smooth muscle cells from the tunica media into the tunica intima. Smooth muscle cells stimulate the formation of collagen. When a foam cell dies it released its lipid content. This combination of cells and debris result in inflammation. This is known as the atheroma plaque.
What is a fatty streak ?
The first stage of atherosclerosis where there is a build up of lipid-laden macrophages in the intima. These can develop in children
Describe the cap of an atheromatous plaque
Over time fatty streaks develop into atheroma plaques which have a central lipid core and a fibrosis cap. The cap contains the collagen and inflammatory cells. In late stages the cap can become calcified and the plaques will merge to cover large areas
Describe the core of an atheromatous plaque
The lipid core is where the debris is and this is very thrombogenic
How do plaques grow ?
Plaques can also grow by forming repeated microthrombi in areas of endothelial cell loss.
Name two things which can happen to an atheroma ?
- A thrombus can develop on it
- It can rupture
What are some risk factors of Atheroma ?
Hypercholesterolemia Hypertension Obesity old age Diabetes
What are the signs and symptoms of atheroma ?
It is usually asymptomatic until it results in an acute condition
How is atheroma treated ?
Prevention, cholesterol lowering drugs. Sometimes surgery.
What is the prognosis of atheroma ?
Thrombosis or ruptured plaque can embolise and cause ischemic stroke or ischemic heart disease
What is a another name for Ischemic heart disease ?
coronary heart disease